UIImage切图

UIImage+CutSize.h

@interface UIImage (CutSize)

- (UIImage*)cutToSize:(CGSize)size;

@end

UIImage+CutSize.m

#import "UIImage+CutSize.h"

@implementation UIImage (CutSize)

- (UIImage*)cutToSize:(CGSize)size{
	UIImage *newImage;
	if (size.width/size.height - self.size.width/self.size.height > 0.01f) {
		
		CGSize imageSize = self.size;
		CGFloat scale = imageSize.width / size.width;
		CGRect rect = CGRectMake(0.0f, (imageSize.height - size.height *scale)/2, size.width*scale, size.height *scale);
		
		CGImageRef imageRef=CGImageCreateWithImageInRect([self CGImage],rect);
		newImage = [UIImage imageWithCGImage:imageRef];
		
		return newImage;
	}else if (size.height/size.width - self.size.height/self.size.width> 0.01f) {
		
		CGSize size = self.size;
		CGFloat scale = size.height / size.height;
		CGRect rect = CGRectMake((size.width - size.width*scale)/2, 0.0f, size.width*scale, size.height*scale);
		
		CGImageRef imageRef=CGImageCreateWithImageInRect([self CGImage],rect);
		newImage = [UIImage imageWithCGImage:imageRef];
		return newImage;
	}
	
	return self;
}

@end